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Blebs
Kinds of Blebs Terms modified by Blebs Selected AbstractsIn Vitro and In Vivo Relaxation of Corpus Cavernosum Smooth Muscle by the Selective Myosin II Inhibitor, BlebbistatinTHE JOURNAL OF SEXUAL MEDICINE, Issue 10 2009Xin-hua Zhang MD ABSTRACT Introduction., Blebbistatin (BLEB) is a small cell permeable molecule originally reported as a selective inhibitor of myosin II isoforms expressed by striated muscle and non-muscle cells (IC50 = 0.5,5 µM) with poor inhibition of turkey gizzard smooth muscle (SM) myosin II (IC50,80 µM). However, recently it was found that BLEB can potently inhibit mammalian arterial SM (IC50,5 µM). Aim., To investigate the effect of BLEB on corpus cavernosum SM (CCSM) tone and erectile function (EF). Methods., CC tissue obtained from penile implant patients along with CC, aorta and bladder from adult male rats were used for BLEB organ bath studies. Intracavernosal BLEB was administered to rats and EF was assessed via intracavernous pressure (ICP). Main Outcome Measures., Effects of BLEB on agonist-induced CCSM, aorta and bladder contraction in vitro and ICP in vivo. Results., BLEB completely relaxed human CCSM pre-contracted with phenylephrine (PE) in a dose-dependent manner decreasing tension by 76.5% at 10 µM. BLEB pre-incubation attenuated PE-induced contraction of human CC by ,85%. Human CC strips pre-contracted with endothelin-1 or KCl were almost completely relaxed by BLEB. Rat CCSM pre-contracted with PE showed BLEB relaxation comparable to human CCSM. BLEB inhibition was similar for rat aorta but slower for bladder. Both maximal ICP and ICP/mean arterial pressure were dose-dependently increased by BLEB intracavernous injections with full erection at 1 micromole. Conclusion., Our novel data reveals that BLEB nearly completely relaxes rat and human CCSM pre-contracted with a variety of potent agonists and exhibits tissue selectivity. Coupled with our in vivo data in which nanomole doses of BLEB significantly increase ICP, our data substantiates an important role for the SM contractile apparatus in the molecular mechanism for EF and suggests the possibility of BLEB binding at myosin II as a therapeutic treatment for ED by targeting SM contractile pathways. Zhang X, Aydin M, Kuppam D, Melman A, and DiSanto ME. In vitro and in vivo relaxation of corpus cavernosum smooth muscle by the selective myosin II inhibitor, blebbistatin. J Sex Med 2009;6:2661,2671. [source] ChemInform Abstract: Facile Synthesis of Functionalized Oligophenothiazines via One-Pot Bromine,Lithium Exchange,Borylation,Suzuki Coupling (BLEBS).CHEMINFORM, Issue 32 2008Adam W. Franz Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] A short history of blebbingJOURNAL OF MICROSCOPY, Issue 3 2008G.T. CHARRAS Summary Blebs are protrusions of the cell membrane. They are the result of actomyosin contractions of the cortex, which cause either transient detachment of the cell membrane from the actin cortex or a rupture in the actin cortex. Then, cytosol streams out of the cell body and inflates the newly formed bleb. During expansion, which lasts ,30 s, the bleb is devoid of actin and the surface area increases through further tearing of membrane from the cortex and convective flows of lipids in the plane of the membrane through the bleb neck. Once expansion slows, an actin cortex is reconstituted. First actin-membrane linker proteins, such as ezrin, are recruited to the bleb, then actin, actin-bundling proteins and finally myosin motor proteins. Retraction lasts ,2 min and is powered by myosin motor proteins. Though it has been less studied than other actin-based membrane protrusions such as lamellipodia or filopodia, blebbing is a common feature of cell physiology during cell movement, cytokinesis, cell spreading and apoptosis. This review will succinctly attempt to summarize what we know about the mechanisms involved in blebbing, when it appears in cell physiology and what open questions remain. [source] Stratus optical coherence tomography study of filtering blebs after primary trabeculectomy with a fornix-based conjunctival flapACTA OPHTHALMOLOGICA, Issue 1 2010Kazuyuki Hirooka Abstract. Purpose:, To investigate the relationship between filtering bleb function and Stratus optical coherence tomography (OCT) images. Methods:, We studied 72 eyes of 65 consecutive patients who had a fornix-based conjunctival flap in primary trabeculectomy with mitomycin C (MMC). Filtering blebs with various types of glaucoma were examined using Stratus OCT. Success rates were defined as intraocular pressure (IOP) , 15 mmHg and IOP reduction , 25% without medication or additional surgery. Success rates among classified groups were compared using Kaplan,Meier survival curves and the log-rank test. Results:, Blebs were classified into three different categories on the basis of the following Stratus OCT patterns: cystoid type (multiple cysts inside the bleb; 17 eyes), diffuse type (low to high reflective areas that were mixed inside the bleb; 31 eyes) and layer type (medium to high reflective layer inside the bleb; 24 eyes). Success rates in the cystoid-, diffuse- and layer-type blebs were 94%, 97% and 75% (P = 0.02), respectively. Conclusion:, In trabeculectomy with MMC and a fornix-based conjunctival flap, there is a significant association between the success rates and the postoperative Stratus OCT findings of filtering blebs. [source] A short history of blebbingJOURNAL OF MICROSCOPY, Issue 3 2008G.T. CHARRAS Summary Blebs are protrusions of the cell membrane. They are the result of actomyosin contractions of the cortex, which cause either transient detachment of the cell membrane from the actin cortex or a rupture in the actin cortex. Then, cytosol streams out of the cell body and inflates the newly formed bleb. During expansion, which lasts ,30 s, the bleb is devoid of actin and the surface area increases through further tearing of membrane from the cortex and convective flows of lipids in the plane of the membrane through the bleb neck. Once expansion slows, an actin cortex is reconstituted. First actin-membrane linker proteins, such as ezrin, are recruited to the bleb, then actin, actin-bundling proteins and finally myosin motor proteins. Retraction lasts ,2 min and is powered by myosin motor proteins. Though it has been less studied than other actin-based membrane protrusions such as lamellipodia or filopodia, blebbing is a common feature of cell physiology during cell movement, cytokinesis, cell spreading and apoptosis. This review will succinctly attempt to summarize what we know about the mechanisms involved in blebbing, when it appears in cell physiology and what open questions remain. [source] Mouse dendritic cells matured by ingestion of apoptotic blebs induce T cells to produce interleukin-17ARTHRITIS & RHEUMATISM, Issue 8 2009Justin H. Fransen Objective Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the formation of antinuclear autoantibodies. Increased apoptosis and reduced clearance of apoptotic material have been assigned a role in the pathogenesis of SLE, but the underlying mechanisms remain elusive. During apoptosis apoptotic blebs are formed in which autoantigens are clustered. The cellular remnants after blebbing are referred to as apoptotic cell bodies. We undertook this study to compare the effects of apoptotic blebs and apoptotic cell bodies on maturation of dendritic cells (DCs) and their T cell stimulatory capacity in a murine setting. Methods The uptake by DCs of apoptotic blebs and apoptotic cell bodies was analyzed by flow cytometry and confocal microscopy. DC maturation and DC-induced T cell activation were determined by measuring expression of costimulatory molecules using flow cytometry and by measuring production of cytokines using enzyme-linked immunosorbent assay. Results DCs internalized apoptotic blebs more efficiently than apoptotic cell bodies. Incubation of DCs with apoptotic blebs resulted in increased CD40 and CD86 expression and increased interleukin-6 (IL-6) and tumor necrosis factor , production, while apoptotic cell bodies had no stimulatory effects. Using chloroquine, apoptotic bleb,induced DC maturation was shown to be independent of Toll-like receptors 3, 7, and 9. Interestingly, in cocultures with allogeneic T cells, bleb-matured DCs induced production of IL-2, interferon-,, and, in particular, IL-17, suggesting a Th1/Th17 response. Conclusion Apoptotic blebs, in contrast to apoptotic cell bodies, induce DC maturation, thereby providing DCs with increased Th17 cell stimulatory capacity. These data imply that apoptotic bleb,induced DC maturation represents an important driving force in the autoimmune response in SLE. [source] Correlation between optical coherence tomography scan and histological specimen of a filtering blebACTA OPHTHALMOLOGICA, Issue 2 2010Kazuyuki Hirooka No abstract is available for this article. [source] The effect of deep sclerectomy on intraocular pressure of normal-tension glaucoma patients: 1-year resultsACTA OPHTHALMOLOGICA, Issue 1 2010Sakari Suominen Abstract. Purpose:, To study the intraocular pressure (IOP)-reducing effect of deep sclerectomy on normal-tension glaucoma (NTG) patients. Methods:, We retrospectively analysed 21 eyes of 18 consecutive NTG patients who had undergone deep sclerectomy with mitomycin-C and a collagen implant. Results:, Median (range) preoperative IOP was 15.1 mmHg (9.3,20.8) and median follow-up time 13 months (12,18). At the 1-year follow-up visit, median IOP was significantly (P < 0.001) reduced to 10.5 mmHg (4,15) with median IOP reduction from preoperative values of 37% (12,78). Laser goniopuncture was performed in 10 eyes (48%) 1,16 months postoperatively. After 13 months' follow-up, a complete success at 20%, 25% and 30% IOP reduction levels was achieved in 67%, 62% and 52% of eyes, respectively. Few complications were encountered, but these included reduced visual acuity, problems with conjunctiva, microperforation, hyphaema, Dellen formation and encapsulated bleb. We encountered no complications related to postoperative hypotony. Conclusion:, Deep sclerectomy with a collagen implant and mitomycin-C was a safe and effective method for reducing IOP in NTG patients during 1-year follow-up. [source] Stratus optical coherence tomography study of filtering blebs after primary trabeculectomy with a fornix-based conjunctival flapACTA OPHTHALMOLOGICA, Issue 1 2010Kazuyuki Hirooka Abstract. Purpose:, To investigate the relationship between filtering bleb function and Stratus optical coherence tomography (OCT) images. Methods:, We studied 72 eyes of 65 consecutive patients who had a fornix-based conjunctival flap in primary trabeculectomy with mitomycin C (MMC). Filtering blebs with various types of glaucoma were examined using Stratus OCT. Success rates were defined as intraocular pressure (IOP) , 15 mmHg and IOP reduction , 25% without medication or additional surgery. Success rates among classified groups were compared using Kaplan,Meier survival curves and the log-rank test. Results:, Blebs were classified into three different categories on the basis of the following Stratus OCT patterns: cystoid type (multiple cysts inside the bleb; 17 eyes), diffuse type (low to high reflective areas that were mixed inside the bleb; 31 eyes) and layer type (medium to high reflective layer inside the bleb; 24 eyes). Success rates in the cystoid-, diffuse- and layer-type blebs were 94%, 97% and 75% (P = 0.02), respectively. Conclusion:, In trabeculectomy with MMC and a fornix-based conjunctival flap, there is a significant association between the success rates and the postoperative Stratus OCT findings of filtering blebs. [source] We're still under pressure: postoperative hypertonyACTA OPHTHALMOLOGICA, Issue 2009I STALMANS Purpose Postoperative hypertony is a frequent complication after trabeculectomy. This problem may occur from the early, to the late stages, and may be an acute or chronic situation. The aim of this lecture is to review the various causes with their clinical presentation and therapeutic strategy. Methods An overview will be provided on the different mechanisms that may cause hypertony after trabeculectomy, ranging from tight flap sutures or blocking of the constructed channel by various substances, over encapsulation and failing bleb to steroid response. For each of these situations, the clinical presentation and differential diagnosis will be discussed. Finally, the therapeutic options will be reviewed. Photographic and video material will be used to illustrate the various clinical presentations and therapeutic interventions. Conclusion This lecture will provide the audience with a practically oriented overview of the clinical management of hypertony after trabeculectomy. [source] Effect of phacoemulsification on the primary open angle glaucoma control after trabeculectomy: a case-control studyACTA OPHTHALMOLOGICA, Issue 2009S AZIZ Purpose In this retrospective and comparative study, we analyzed the influence of phacoemulsification (PE) on the glaucoma control in case patients (trabeculectomy-phacoemulsification [CE]) compared with the control that underwent trabeculectomy (T) alone in eyes with primary open angle glaucoma (POAG). Methods Twenty one patients who underwent PE subsequent to T were identified, and 41 who underwent T alone were matched. Visual acuity (VA), intraocular pressure (IOP), bleb appearance, vertical cup disc ratio (VCDR), visual field (VF), glaucoma medications, iris manipulation and complications were documented. Mean follow up was 12 months. Success was defined when IOP , 21 mmHg with the abscense of glaucoma medication and/or further surgical intervention. Results Patients in CE group had no significant change in IOP from pre-operative measures to 12 months post-operative (p=0.001). The mean IOP reduced from 15.3 mm Hg to 14.7 mmHg postoperatively. The control group showed an average IOP reduction of 6 mm Hg in the last visit. In CE group, 19% required 1 or 2 glaucoma medications at one year fellow-up vs 19.5% in the control group. In CE group 9.5% showed flattening of previously formed bleb in the last visit (P<0.001), 9.7 % ended with flat bleb in the T group. The increase in VCDR for the CE group was statistically significant when compared to the control group (p<0.001). Patients in CE group were more likely to exhibit a change in VF (47.6% versus 7.3% respectively). The study is limited by the small number of cases available. Conclusion Corneal PE in eyes with filtering blebs does not adversely affect long-term glaucoma control in patients with POAG. [source] Phacoemulsification in trabeculectomized eyesACTA OPHTHALMOLOGICA, Issue 5 2005Pia Ehrnrooth Abstract. Purpose:,To evaluate retrospectively risk indicators for cataract surgery and the effect of phacoemulsification on intraocular pressure (IOP) control in eyes that have undergone trabeculectomy. Methods:,We undertook a retrospective analysis of 138 eyes with primary open-angle glaucoma (POAG) or exfoliation glaucoma (EG) in 138 consecutive patients over the age of 40 years undergoing trabeculectomy with no antimetabolites performed by one surgeon. Of the 48 eyes (35%) undergoing a cataract operation during the follow-up period of 2,5 years, 46 were included in this analysis. Their IOP, glaucoma medication and best corrected visual acuity (BCVA) before cataract surgery and at the last follow-up were compared. Risk indicators for cataract surgery were analysed. Results:,Cataract operations were performed 5.1,58.1 months (median 14.4 months) after trabeculectomy. The mean length of follow-up after cataract surgery was 25.3 months (SD 12.9, median 24.8 months). Before cataract surgery, the mean IOP was 16.2 mmHg (SD 4.9) and the mean number of topical antiglaucoma medicines 0.8 (SD 1.0). At the most recent visit, mean IOP was 17.3 mmHg (SD 6.4) (p = 0.35), and the mean number of medicines was 1.3 (SD 1.1) (p = 0.0007). Of the 22 eyes in which treatment had been categorized as completely successful (IOP ,,21 mmHg without other therapy) before cataract surgery, 13 (59%) had remained so. The number of failures (IOP >,21 mmHg, or more than one medication needed or further surgery performed) increased from 14 (30%) before surgery to 28 (61%) afterwards. The proportion of failures in the cataract surgery group was twice that in the no cataract surgery group (61% versus 31%). In a proportional hazards regression, only age (73.9 years [SD 9.4] and 68.1 years [SD 9.8] in patients with and without cataract surgery, respectively) proved to be a significant (p = 0.001) indicator for surgery. Conclusion:,The results of this retrospective study on consecutive clinical cases of trabeculectomy indicate that cataract progression after trabeculectomy is mainly an age-related process. In more than half the eyes with good preoperative IOP control, this good control was maintained after cataract surgery. On the other hand, in some eyes cataract surgery may compromise IOP control even when surgery avoids the area of the bleb. [source] Histopathology of a functioning mitomycin-C trabeculectomyCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 3 2009Steve Y-W Liang MBBS Abstract The ideal trabeculectomy bleb is diffuse, normally vascularized and characterized by microcystic change in the overlying conjunctiva. We compare and contrast the histopathology of a normally functioning mitomycin-C trabeculectomy site obtained from an eye enucleated for iris melanoma with abnormal blebs discussed in the literature. Representative sections of the normally functioning bleb were examined under the light microscope. The conjunctiva is composed of a uniform three-layered non-keratinizing stratified squamous epithelium overlying a single layer of oedematous basal cells. The conjunctival stroma consisted of loose connective tissue, traversed by capillaries and scattered small cystic spaces lined by endothelial cells. There were no goblet cells and few inflammatory cells and fibroblasts. The scleral trapdoor was evident as a cleft in the scleral wall in communication with the anterior chamber at the surgically created sclerostomy. Because the histopathological findings in our case correlate well with this clinical appearance, we conclude that whereas augmentation with anti-metabolites, such as mitomycin-C, can be associated with significantly altered conjunctival histopathology and consequent hypotony, but, if used carefully, normal architecture is conserved. [source] Inadvertent sclerostomy with encysted bleb following trans-scleral contact diode laser cyclophotocoagulationCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 1 2006Viney Gupta MD Abstract A 22-year-old woman underwent 360° trans-scleral contact diode laser cyclophotocoagulation for refractory glaucoma. Conjunctival burns and scleral thinning were noticed inferonasally at the last laser application. Intraocular pressure in the first week was normal. Six months later the patient presented with encysted filtering bleb and high intraocular pressure. Ultrasound biomicroscopy revealed a full thickness sclerostomy. This report suggests that inadvertent sclerostomy may present with encysted bleb months after trans-scleral contact diode laser cyclophotocoagulation. [source] Systemic anti-inflammatory fibrosis suppression in threatened trabeculectomy failureCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 1 2004Brendan Vote FRANZCO Abstract Purpose:,To provide a rationale for the use of systemic anti-inflammatory fibrosis suppression in the postoperative management of threatened early trabeculectomy bleb failure. Methods:,A review of the literature and of the authors' own experiences was conducted. Results:,The most important cause of persistent elevation of intraocular pressure after trabeculectomy is unduly marked or persistent inflammation with deposition of fibrous tissue, which prevents the formation of an adequately draining bleb. It was found that a clinically useful degree of suppression of bleb inflammation and fibrosis can be obtained with a 4,6 week course of the combined systemic administration of prednisone (10 mg t.i.d.), a non-steroidal anti-inflammatory agent (e.g. diclofenac 100 mg SR daily) and colchicine (0.25 mg or 0.3 mg t.i.d.), which was termed anti-inflammatory fibrosis suppression. Topical atropine 1% t.i.d. and adrenaline 1% t.i.d. eye drops can also be considered in addition to routine postoperative topical steroids. Conclusions:,Despite advances in surgical techniques and methods to control fibrosis, anti-inflammatory fibrosis suppression is a valuable tool to have available in the postoperative period for management of trabeculectomies that threaten failure. This regime produces a diffuse bleb, which has a very low risk of late infection or bleb perforation. It is recommend that this regime be added to the list of therapies that are considered when clinical features suggestive of a failing bleb are confronted early in the postoperative course. [source] Preparing to move: Assembly of the MSP amoeboid motility apparatus during spermiogenesis in AscarisCYTOSKELETON, Issue 4 2005Maria Antonia Rodriguez Abstract We exploited the rapid, inducible conversion of non-motile Ascaris spermatids into crawling spermatozoa to examine the pattern of assembly of the MSP motility apparatus that powers sperm locomotion. In live sperm, the first detectable motile activity is the extension of spikes and, later, blebs from the cell surface. However, examination of cells by EM revealed that the formation of surface protrusions is preceded by assembly of MSP filament tails on the membranous organelles in the peripheral cytoplasm. These organelle-associated filament meshworks assemble within 30 sec after induction of spermiogenesis and persist until the membranous organelles are sequestered into the cell body when the lamellipod extends. The filopodia-like spikes, which are packed with bundles of filaments, extend and retract rapidly but last only a few seconds before giving way to, or converting into, blebs. Coalescence of these blebs, each supported by a dense mesh of filaments, often initiates lamellipod extension, which culminates in the formation of the robust, dynamic MSP fiber complexes that generate sperm motility. The same membrane phosphoprotein that orchestrates assembly of the fiber complexes at the leading edge of the lamellipod of mature sperm is also found at all sites of filament assembly during spermiogenesis. The orderly progression of steps that leads to construction of a functional motility apparatus illustrates the precise spatio-temporal control of MSP filament assembly in the developing cell and highlights the remarkable similarity in organization and plasticity shared by the MSP cytoskeleton and the actin filament arrays in conventional crawling cells. Cell Motil. Cytoskeleton 60:191,199, 2005 © 2005 Wiley-Liss, Inc. [source] Urine cytology in renal glomerular disease and value of G1 cell in the diagnosis of glomerular bleedingDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2003Gia-Khanh Nguyen M.D. Abstract The objectives of the present study were to evaluate the cytology of urine sediments in patients with glomerular diseases, as well as the value of G1 dysmorphic erythrocytes (G1DE) or G1 cells in the detection of renal glomerular hematuria. Freshly voided urine samples from 174 patients with glomerular diseases were processed according to the method used for semiquantitative cytologic urinalysis. G1DEs (distorted erythrocytes with doughnut-like shape, target configuration with or without membranous protrusions or blebs), non-G1DEs (distorted erythrocytes without the above-mentioned morphologic changes), normal erythrocytes (NEs), and renal tubular cells (RTCs) were evaluated. Erythrocytic casts (ECs) were counted and graded as abundant (>1 per high-power field) or rare (1 per 5 high-power fields). G1DE/total erythrocyte ratios were calculated by counting 200 erythrocytes including G1DEs, non-G1DEs, and NEs. Only abundant NEs were found in 13 cases; abundant G1DEs, non-G1DEs, NEs, and no ECs in 95 cases; abundant NEs, non-G1DEs, and ECs and no G1DEs in 31 cases; and abundant NEs, G1DEs and non-G1DEs, and rare ECs in 35 cases. In 130 cases in which G1DEs were present, the G1DE/total erythrocyte ratios varied from 10% to 100%. This parameter was greater or equal to 80%, 50%, 20%, and 10% in 58 (44.6%), 29 (22.3%), 28 (21.5%), and 15 (11.5%) patients, respectively. In all cases, the number of RTCs was within normal limits or slightly increased, and a variable number of non-G1DEs were present in 161 cases. Thus, abundant ECs and/or G1DEs with a G1DE/total erythrocyte ratio of 10,100% proved to be specific urinary markers for renal glomerular diseases. Diagn. Cytopathol. 2003;29:67,73. © 2003 Wiley-Liss, Inc. [source] Light and electron microscopic study of the anterior oesophagus of Bulla striata (Mollusca, Opisthobranchia)ACTA ZOOLOGICA, Issue 2 2010Alexandre Lobo-da-Cunha Abstract Lobo-da-Cunha, A., Oliveira, E., Alves, Â., Coelho, R. and Calado, G. 2010. Light and electron microscopic study of the anterior oesophagus of Bulla striata (Mollusca, Opisthobranchia). ,Acta Zoologica (Stockholm) 91: 125,138. The anterior oesophagus of Bulla striata was investigated with light and electron microscopy. In the most anterior region, the ridges of the oesophageal wall are covered by a ciliated columnar epithelium forming large apical blebs which are released into the lumen, an activity that is particularly intense in the oesophageal pouch. In the last two-thirds of the anterior oesophagus, the epithelium is covered with microvilli embedded in a cuticle, but apocrine secretion and cilia are absent. Subepithelial secretory cells are very abundant in the oesophageal wall, except in the roof of the pouch. They have a long neck that crosses the epithelium, whereas the cell body containing the nucleus is embedded in the connective tissue. Large electron-lucent secretory vesicles and many Golgi stacks fill most of their cytoplasm. The histochemical and cytochemical assays show that these cells secrete acid mucopolysaccharides. With the current and future studies we aim to obtain data for the establishment of relationships between morphofunctional features of the digestive system and food types in cephalaspideans. Additionally, the new data about the oesophageal pouch of B. striata may be useful for the establishment of eventual homologies with the oesophageal diverticula of other opisthobranchs. [source] Differentiation of the epidermis of scutes in embryos and juveniles of the tortoise Testudo hermanni with emphasis on beta-keratinizationACTA ZOOLOGICA, Issue 3 2005L. Alibardi Abstract The sequence of differentiation of the epidermis of scutes during embryogenesis in the tortoise Testudo hermanni was studied using autoradiography, electron microscopy and immunocytochemistry. The study was mainly conducted on the epidermis of the carapace, plastron and nail. Epidermal differentiation resembles that described for other reptiles, and the embryonic epidermis is composed of numerous cell layers. In the early stages of differentiation of the carapacial ridge, cytoplasmic blebs of epidermal cells are in direct contact with the extracellular matrix and mesenchymal cells. The influence of the dermis on the formation of the beta-layer is discussed. The dermis becomes rich in collagen bundles at later stages of development. The embryonic epidermis is formed by a flat periderm and four to six layers of subperidermal cells, storing 40,70-nm-thick coarse filaments that may represent interkeratin or matrix material. Beta-keratin is associated with the coarse filaments, suggesting that the protein may be polymerized on their surface. The presence of beta-keratin in embryonic epidermis suggests that this keratin might have been produced at the beginning of chelonian evolution. The embryonic epidermis of the scutes is lost around hatching and leaves underneath the definitive corneous beta-layer. Beneath the embryonic epidermis, cells that accumulate typical large bundles of beta-keratin appear at stage 23 and at hatching a compact beta-layer is present. The differentiation of these cells shows the progressive replacement of alpha-keratin bundles with bundles immunolabelled for beta-keratin. The nucleus is degraded and electron-dense nuclear material mixes with beta-keratin. In general, changes in tortoise skin when approaching terrestrial life resemble those of other reptiles. Lepidosaurian reptiles form an embryonic shedding layer and crocodilians have a thin embryonic epidermis that is rapidly lost near hacthing. Chelonians have a thicker embryonic epidermis that accumulates beta-keratin, a protein later used to make a thick corneous layer. [source] Cell surface analysis of the lipid-discharging obligate hydrocarbonoclastic species of the genus AlcanivoraxEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 6 2010Alvin Brian Lange Abstract This study presents novel information useful for addressing the question how species of the genus Alcanivorax discharge triacylglycerols (TAG) and/or wax esters (WE). The observed structures were referred as "blebs" according to Gauthier et al.1 to avoid confusion with other discharging phenomena. The cells were aerobically cultivated on solid media and not in liquid media to maintain the cells in the native state, and were investigated by transmission electron microscopic (TEM) and scanning electron microscopic (SEM) methods to document the surface structures of the cells. The phenomenon of lipid export could be allocated to three phases: phase I: protrusion formation of the cell membrane occurred; phase II: discharging progressed further with blebs becoming larger; and phase III: the blebs at the cell surface were separated from the cells. Using freeze-fracture micrographs by TEM, vesicle experiments and TLC, we have shown that the blebs contained TAGs and WEs. The results shown in this study will support further research to unravel the unknown discharging mechanism. In addition, the formation of an extensive extracellular matrix was observed by SEM. [source] Death-associated protein kinase (DAPK) and signal transduction: blebbing in programmed cell deathFEBS JOURNAL, Issue 1 2010Miia Bovellan Death-associated protein kinase (DAPK) regulates many distinct signalling events, including apoptosis, autophagy and membrane blebbing. The role of DAPK in the blebbing process is only beginning to be understood and, in this review, we will first summarize what is known about the cytoskeletal proteins and signalling cascades that participate in bleb growth and retraction and then highlight how DAPK integrates with these processes. Membrane blebs are quasispherical cellular protrusions that have a lifetime of approximately 2 min. During expansion, blebs are initially devoid of actin, although actomyosin contractions provide the motive force for growth. Once growth slows, an actin cortex reforms and actin-bundling and contractile proteins are recruited. Finally, myosin contraction powers bleb retraction into the cell body. Blebbing occurs in a variety of cell types, from cancerous cells to embryonic cells, and can be seen in cellular phenomena as diverse as cell spreading, movement, cytokinesis and cell death. Although the machinery that executes this is still undefined in detail, the conservation of blebbing phenomenon suggests a fundamental role in metazoans and DAPK offers a door to further dissect this fascinating process. [source] Mineral evolution of a garnet-pyroxenite nodule within eclogite, eastern Sulu ultrahigh-pressure metamorphic terrane, East ChinaJOURNAL OF METAMORPHIC GEOLOGY, Issue 8 2005T. N. YANG Abstract Detailed microtextural observations and bulk chemical analysis were undertaken on a garnet-pyroxenite nodule within retrograde eclogites from the NE Sulu ultrahigh-pressure metamorphic (UHPM) terrane. The results suggest that the protolith was a cumulate from a gabbroic body. The nodule consists primarily of coarse clinopyroxene grains with a very high content of the Ca-Tschermakite molecule. Microscopic observations and back-scattered electron images (BSE) demonstrate a complicated intergrowth of clinopyroxene, garnet and ilmenite, which represents the peak metamorphic assemblage. The primary clinopyroxene grains are armoured with a thin garnet corona up to 0.5 mm wide that forms an interconnected network. Within the clinopyroxene grains, four sets of garnet lamellae are distributed along crystallographic planes; locally, a vermicular intergrowth of garnet and diopside is developed. Besides the garnet, parallel arrays of ilmenite blebs are common within the clinopyroxene. Hydrous minerals such as amphibole, zoisite and titanite formed at later stages, and replaced diopside, garnet and ilmenite respectively. The P,T conditions determined for the formation of the garnet lamellae indicate that the garnet pyroxenite experienced UHP metamorphism at the same peak P,T condition as its host eclogite. The very high Ca-Tschermakite content (31,34 mol.%) of the primary clinopyroxene indicates crystallization at about 9,17 kbar and 1250,1450 °C, and together with the microtextural observations, suggests that the protolith of the garnet pyroxenite was a cumulate from a former gabbroic body, in which case, the host eclogite might represent the gabbroic body. [source] A "mesosiderite" rock from northern Siberia, Russia: Not a meteoriteMETEORITICS & PLANETARY SCIENCE, Issue S12 2002Allan H. TREIMAN Although this rock resembles a mesosiderite in its hand-sample aspect and in having Ni-bearing iron metal, it is not a meteorite. This inference is based on the lack of a fusion crust, the lack of cosmogenic nuclides, oxygen with terrestrial isotope ratios, and several mineral chemical criteria. Most likely, the rock is from the iron-metal-bearing basalts of the Siberian Trap basalt sequence, which are mined for their base and platinum-group metals. Mesosiderite imposters like this may be recognized by (1) the presence of Cu metal in hand sample or as microscopic blebs in the low-Ni metal (kamacite), (2) the absence of high-Ni metal (taenite), and (3) the presence of iron carbide (cohenite) enclosing the kamacite. Even if these macroscopic tests are inconclusive, isotopic and mineral chemical tests will also distinguish rocks like this from mesosiderites. [source] Ultrastructural features of bone marrow cells from patients with acquired sideroblastic anemiaMICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2004Meir Djaldetti Abstract The ultrastructural findings of the bone marrow cells from 15 patients with acquired sideroblastic anemia are presented. The red cell precursors from all patients showed the presence of electron-dense material in the mitochondria, representing most probably iron deposits. A great number of these mitochondria were completely destroyed. The erythropoietic precursors from one of the patients showed markedly elongated mitochondria that measured up to 3 ,m. In addition numerous cytoplasmic vacuoles were observed. The red cell precursors from 60% of the patients showed signs of dyserythropoiesis, such as incomplete nuclear division and nuclear distortion. The polymorphonuclears from 47% of the patients presented nuclear abnormalities expressed as nuclear bridges, appendices, and blebs. In addition, phagocytosis of red blood cells was observed. The results of the study underline the advantages of the transmission electron microscope examination in visualization of intricate alterations in hematopoietic cells that cannot be detected with a light microscope. Microsc. Res. Tech. 63:155,158, 2004. © 2004 Wiley-Liss, Inc. [source] Recurrent pneumothoraces associated with nocturnal noninvasive ventilation in a patient with muscular dystrophyPEDIATRIC PULMONOLOGY, Issue 1 2002Lee R. Choo-Kang MD Abstract Although a common complication of mechanical ventilation in acute respiratory failure, spontaneous pneumothorax has been rarely reported among patients on chronic, intermittent, noninvasive positive pressure support. We report the first case of recurrent pneumothoraces associated with nocturnal bilevel positive airway pressure ventilation via a nasal mask. A 26-year old man with chronic respiratory failure secondary to an unclassified neuromuscular condition suffered four separate episodes of spontaneous pneumothorax over a 12-month period. Two episodes occurred while he was asleep on bilevel positive airway pressure support. He was found to have numerous subpleural blebs, and we propose a mechanism for their development. Following open pleurodesis and blebectomy, the patient has not had another pneumothorax. Given the increasing utilization of chronic nocturnal bilevel positive airway pressure ventilation, we suggest that healthcare providers and patients be made aware of this potentially life-threatening complication. Pediatr Pulmonol. 2002; 34:73,78. © 2002 Wiley-Liss, Inc. [source] Photosensitivity in lupus erythematosusPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 5 2004Noah Scheinfeld Background: Lupus erythematosus is a systemic disease process that may manifest with a variety of internal and cutaneous findings. Photosensitivity is one the most common manifestations of lupus erythematosus. In patients with lupus erythematosus, there is a relationship between exposure to ultraviolet light, autoantibodies, genetics and other factors in the development of photosensitivity. Methods: Literature was reviewed on the topics of lupus erythematosus and photosensitivity discussed together and separately. The suggested mechanisms for their relationship were reviewed and analyzed. Results: Photosensitivity's relationship to and influence on the systemic manifestations of lupus remain to be defined. Mechanisms for photosensitivity might include: modulation of autoantibody location, cytotoxic effects, apoptosis induction with autoantigens in apoptotic blebs, upregulation of adhesion molecules and cytokines, induction of nitric oxide sythase expression and ultraviolet-generated antigenic DNA. Tumor necrosis factor , also seems to play a role in the development of photosensitivity. Conclusion: The basis for photosensitivity in lupus has yet to be fully defined. It is more commonly associated with subacute and tumid lupus erythematosus than with other variants. Anti-Ro antibodies appear to relate to photosensitivity. Tumor necrosis factor , polymorphisms appear to be important in some variants of lupus with photosensitivity. There is no sin que non antibody or mutation of photosensitivity in lupus. In patients with lupus, more work needs to be done to define the mechanisms of photosensitivity. [source] Quantitative proteome analysis of detergent-resistant membranes identifies the differential regulation of protein kinase C isoforms in apoptotic T cellsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 15 2010Therese Solstad Abstract Several lines of evidence suggest that detergent-resistant membranes (DRMs) (also known as lipid rafts and glycosphingolipid-enriched microdomains) may have a role in signaling pathways of apoptosis. Here, we developed a method that combines DRMs isolation and methanol/chloroform extraction with stable isotope labeling with amino acids in cell culture-based quantitative proteome analysis of DRMs from control and cisplatin-induced apoptotic Jurkat T cells. This approach enabled us to enrich proteins with a pivotal role in cell signaling of which several were found with increased or decreased amounts in DRMs upon induction of apoptosis. Specifically, we show that three isoforms of protein kinase C (PKC) are regulated differently upon apoptosis. Although PKC, which belongs to the group of conventional PKCs is highly up-regulated in DRMs, the levels of two novel PKCs, PKC, and PKC,, are significantly reduced. These alterations/differences in PKC regulation are verified by immunoblotting and confocal microscopy. In addition, a specific enrichment of PKC, in apoptotic blebs and buds is shown. Furthermore, we observe an increased expression of ecto-PKC, as a result of exposure to cisplatin using flow cytometry. Our results demonstrate that in-depth proteomic analysis of DRMs provides a tool to study differential localization and regulation of signaling molecules important in health and disease. [source] Apoptosis in the Myocardium of the Adult Dromedary Camel: Ultrastructural CharacterizationANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2010A.-H. K. Osman Summary Apoptosis is a highly regulated mode of cell death that occurs in the absence of inflammation. Light microscopic (LM) examination of the myocardium of apparently healthy camel did not reveal evidence of apoptosis in any samples; however, evidence of apoptosis was apparent by transmission electron microscopy (TEM). The most common apoptotic features observed by TEM included (1) an intact sarcolemma with some bleb formation; (2) nuclear chromatin condensation and margination with nucleolar disruption; (3) mitochondrial swelling and disorganization, accompanied by degeneration or hypercondensation of cristae; and (4) an intercalated disc region with a higher-than-normal mitochondrion/myofibril ratio, or surrounded from both sides by asymmetrically contracted sarcomeres. Apoptotic alterations were also noted among the endothelial cells lining the microvasculature of the myocardium. These alterations included (1) marked nuclear chromatin condensation and margination; (2) villous blebs on the adluminal plasmalemma, which projected into the lumen; (3) cytoplasmic vacuolation; (4) presence of intraluminal membrane-bounded vesicles; and (5) occasional pericapillary edema and accumulations of cellular debris. The results of this study indicate that myocardial apoptosis can occur in apparently healthy camels, in the absence of a clear-cut etiology. [source] The Gross and Micro Anatomy of the Accessory Sex Glands of the Male Agouti (Dasyprocta leporina)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009W. M. Mollineau Summary This study was a follow up to the study on the gross anatomy of the male agouti (Dasyprocta leporina) reproductive system. The seminal vesicles of the agouti are lobulated structures. The mean diameter of the large lumen is 883.6 ± 76.83 ,m. The mucosa (24.1 ± 0.92 ,m), which is lined by pseudo-stratified columnar epithelium is thrown into folds, which often branch. The lamina muscularis mucosa is thin and is made of loose connective tissue containing blood vessels. The mucosa of the leaf-like coagulating glands of the agouti is folded. The mean diameter of the lumen is 488.3 ± 41.96 ,m. The mucosa contains tubuloalveolar glands, which have a mean length of 199.5 ± 28.83 ,m. The thin epithelium, 15.0 ± 1.25-,m wide, consists mostly of pseudo-stratified columnar cells. The epithelium also has surface modifications in the form of apical blebs and cilia. The epithelium of the agouti's lobulated prostate gland is also folded creating a large lumen with a mean diameter of 995.5 ± 55.70 ,m. The mucosa contains tubular and tubuloalveolar glands, each having a mean length of 134.4 ± 13.59 ,m. The epithelium (13.9 ± 1.16 ,m) consists of pseudo-stratified columnar cells. The pea-shaped bulbourethral gland (BG) of the agouti consists of convoluted tubular, mucous secretory units, which are irregularly shaped each with a mean length of 177.9 ± 7.10 ,m and a mean width of 63.5 ± 3.97 ,m. The BG of the agouti are ventro-lateral to the rectum and dorsally positioned to the pubic symphysis, and connected to the urethra by short ducts. [source] Electron Microscopic Study of the Porcine Choroid Plexus EpitheliumANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2008W. De Spiegelaere Summary The choroid plexus (CP) is a highly vascularized organ in the brain ventricles which acts as the main producer of cerebrospinal fluid (CSF). A study of the surface ultrastructure of the porcine CP was performed using scanning and transmission electron microscopy. The vascular walls of the capillaries were fenestrated. Epiplexus cells of different morphology were abundant on top of the epithelial surface. Two types of epithelial cells were present, characterized by the presence or absence of microvilli. Some epithelial cells contained cilia while other cells had large secretory protrusions called blebs. In the choroid epithelium of the lateral ventricles, some cells with large depressions were present. Cells with peduncles, such as recently discovered in the buffalo, could not be recognized. The variability of the choroidal surface structures clearly indicates the active role of the CP in the formation and maintenance of the CSF and its components. [source] | |||||||||||||||||||